Air bulb for atomizers and method of making same



July 28, 1959 A. R. HENDRY 2,896,840

AIR BULB FOR ATOMIZERS AND METHOD OF MAKING SAME Filed'Nov. 20, 1956lNl/ENTOR. ADOL'PH R. HENDRY A for/1e ys.

United States Patent AIR BULB FOR ATOMIZERS AND METHOD OF MAKING SAMEAdolph R. Hendry, Portland, Greg.

Application November 20, 1956, Serial No. 623,376

2 Claims. (Cl. 230-169) This invention relates to improvements in airbulbs for supplying pressured air to atomizer receptacles or the like,and a method of making the air bulbs and is a continuation-in-part of myapplications, Serial No. 277,327, filed March 18, 1952 and Serial No.309,267, filed September 12, 1952, both abandoned.

Air bulbs heretofore used with atomizers, nebulizers, and the like, havebeen found to be objectionable for various reasons, one of which istheir inability to function properly after a short period of usage. Suchdifiiculty arises principally from the backflow of fluid into valvestructures utilized in connection with the bulbs. Such fluid isgenerally sticky, and, upon reaching the valves, will cause them to berendered partially or wholly inoperative and the bulbs useless for theirintended purpose. Another objectionable feature of prior bulbs residesin their method of production or manufacture, in that they are incapableof being mass produced at low cost, this objection arising principallyfrom the manner of molding and the difficult and time consuming, as wellas expensive, installation of inlet and outlet valve means for causingair to move in one direction through the bulbs. Metallic ball checkvalves are ordinarily employed, involving joints and connections subjectto air leakage. Flap valves heretofore proposed have provedunsatisfactory, being subject to sticking so that they would not openproperly and subject to distortion when the bulb is compressed, so thatthey would not seat properly.

The present invention has as its general object to provide an air bulbfor atomizers or the like which is more efiicient in operation thandevices heretofore known, which will have a long life of satisfactoryperformance and which is economical to manufacture.

More specifically, objects of the invention are to provide an improvedair bulb having a flap type check valve at the inlet end and anunobstructed discharge passage at the opposite end having a pipe andorifice friction greater than the orifice friction at the inlet to causerapid filling of the bulb through the inlet valve and prevent backfiowof air or liquid into the bulb from the discharge passage; to provide anair bulb having an improved flap valve structure and seat therefor; toprovide an air bulb having an inwardly projected valve seat which isnon-distortable to maintain its configuration when the bulb iscompressed for assuring a positive seating of the valve regardless ofthe manner in which the bulb is compressed; and to provide an improvedflap valve construction.

A further object is to provide an improved method for making an air bulband flap valve of the type described.

The present invention comprises an air bulb which may be used for amultitude of different purposes, but its most common use, and as shownand described herein, is in connection with atomizer or nebulizerreceptacles wherein said bulb supplies pressure thereto to produce aspray or vapor. The air bulb embodying the instant invention is moldedfrom rubber and is made initially in two -part-s or halves which meet ina transverse plane at substantially the largest diameter of the finishedHulb.

2,8963% Patented July 28, 1959 One half of the bulb has an inlet orificeor passage controlled by a flap valve, and the other half is providedwith a tube having a central unobstructed passage communicating with theinterior of the bulb. The tube is connected to the atomizer or nebulizerfor aspirating liquid therefrom by pressured air supplied from the bulb.The flap valve which controls the flow of air through the inlet orificeallows air to pass through the bulb in only one direction, said valvepreventing the escape of air 0 through the inlet orifice when the bulbis compressed and permitting air to enter through said inlet orificewhen the bulb is released and is expanding.

In the manufacture of the bulb the valve is molded as an integral partof an inward projection and is formed by a transverse cut which extendssubstantially through the projection but stops short sufficiently toprovide a hinge for the valve. This valve is sufiiciently thin andflexible to readily lift off its seat upon the creation of a vacuumwithin the bulb, and because it is cut from the projection it willconform exactly to its seat to provide a positive seal, the inletorifice extending substantially through the projection into the plane ofthe cut, thereafter to be opened and closed by the operation of thevalve.

The product and method of the invention will be better understood andadditional objects and advantages will become apparent from thefollowing description taken in connection with the accompanying drawingswhich illustrate preferred forms of the device. It is to be understood,however, that the invention may take still other forms and that all suchmodifications, and variations Within the scope of the appended claimswhich will occur to persons skilled in the art are included in theinvention.

In the drawings:

Figure 1 is an elevational view of an atomizer utilizing the present airbulb as a part thereof;

Figure 2 is an enlarged plan view of the atomizer with some parts beingshown in section and some parts being broken away;

Figure 3 is an elevational view of a nebulizer using the present bulb,with some parts being broken away;

Figure 4 is an end elevational view of the inlet or valve end of thebulb, looking into the bulb;

Figure 5 is an enlarged fragmentary view of the valve boss, taken on theline 55 of Figure 4;

Figure 6 is a perspective view of the inlet or valve end of the bulbturned inside out and showing the operation of cutting the valve flap;

Figure 7 shows the boss of Figure 5 after the valve flap has been cut,the flap being lifted ofi its seat; and

Figure 8 is a fragmentary sectional View of a modified form of theinvention. a

In order to appreciate the advantages of the invention, it will first benecessary to describe the construction and operation of certain commondevices with which it is used.

Referring to the drawing, the numeral 10 designates a preferred air bulbstructure of the present invention. In Figures 1 and 2 the bulb 10 isshown mounted on an atomizer receptacle 12, and in Figure 3 the bulb isshown mounted on a nebulizer receptacle 14. The atomizer shown inFigures 1 and 2 is of a type in common use, having a vertical liquidsuction tube 15 extending almost to the bottom of the receptacle andconnected with a horizontal spray tube 15a having a nozzle 17 on itsouter end. An air tube 16 is equipped with a connector fitting 18 at oneend at its other end is connected with a reduced orifice passage 19 inthe nozzle 17 adjacent a similar discharge orifice for the liquid tube15a.

The nebulizer receptacle1'4 of Figure 3 has an' outlet spout or nozzle20 on one side through which vapor is ejected and has an air inlet orbreather tube 21 on its opposite side. Mounted in the receptacle 1 4 isa vertical liquid suction tube 22 and a horizontal nozzle 23 having avery small discharge orifice located to direct pressured air across thetop of the suction tube 22. Nozzle 23 communicates with a connectingtube 25. This air stream draws up liquid from the suction tube 22 anddirects it against a glass ball 26 which breaks up the droplets ofliquid into an air-suspended vapor for producing a slow movingcloud-like ejection from the spout 20. The nebulizer is especiallyintended for medicinal preparations to be inhaled into the nasal andthroat passages in a more finely divided condition than can be producedby an ordinary atomizer, as shown in Figure 2.

The air bulb 10, which is the subject of the present invention, isformed of two halves or parts 30 and 31, the numeral 32 designating theinside surface of the bulb parts and the numeral 33 designating theoutside surface. The two parts are molded separately and then vulcanizedtogether at their meeting edges in a final operation to form thecompleted bulb. The bulb halves are made of a suitable flexible andresilient rubber which is readily distorted by squeezing in the hand tothe positions shown in Figures 2 and 3 for producing a discharge ofpressured air.

The bulb half 30 has an integral tubular stem 35 which provides aconvenient means of attachment to the connector tubes 18 or 25 of theatomizer or nebulizer receptacles, respectively, as shown in thedrawings, the end of this stem being flexed sufficient to fit tightly onsaid tubes. The other half 31 of the bulb is provided with a thickenedend portion 37 having a central aperture or hole 38 forming an inletorifice. This end portion has an inward projection or boss 40, the innerend of which is disposed a substantial distance from the end of thebulb. Molded as a part of the projection 40 is a thin extension or step42 adapted to form a flap valve. The hole 38 extends from the outer endof the thickened end portion 37 inwardly to a point substantiallythrough the projection 40, terminating in the extension 42. Before thetwo halves of the bulb are vulcanized together in a final operation, thegreater part of the extension 42 is transversely cut from the projection40 in the plane of the end face 45 of said projection to form a thindisc or flap seated on said end. The cut which severs the extensionextends substantially therethrough but stops short sufficiently toprovide a hinge 43 for the valve 42, said valve being flexible so thatit may readily lift off its seat when a vacuum is created in the bulb.

The extension or valve 42 has a thickened center portion 44 forming ashort boss for reinforcing the valve across the orifice 38 to preventcollapse of the valve upon the existence of pressure within the bulb.Hole 38 extends slightly beyond the plane of end face 45 andsubstantially into boss 44, the latter thereby providing a substantiallyuniform thickness of material in the valve flap. As best seen in Figure4, the valve 42 has a smaller transverse dimension than the projection40 whereby said valve is protected by the projection from engagementwith the side walls of the bulb when the bulb is compressed.

The pipe friction in tubes 35 and 16, or 35 and 25, plus the orificefriction at 19 or 23, act as a check to restrain the backfiow of air tothe bulb as the bulb is expanding after being compressed. As only a verysmall amount of air in the stem 35 returns to the bulb when the bulb isexpanding, any mist or vapors sucked back into the discharge orificewill not travel far enough through the tubes to reach the bulb by thetime the quick acting inlet valve is wide open to immediately relievethe vacuum and stop the backflow. The quick and wide opening of thevalve thus permits the use of an unobstructed passage at the forward endof the bulb and obviates the necessity for a check valve in thedischarge passage. When a conventional ball check type of valve is usedat the inlet, the opening thereof by re-expansion of the bulb is notquick enough or wide enough to pre vent excessive backflow through thedischarge tube and orifice without an outlet check valve. Excessivebackflow draws mist and vapors back into the bulb causing the valves tostick and rendering the whole device useless.

In Figures 2, 3 and 7 the valve is just starting to open upon release ofthe squeezed bulb. As air rushes in through inlet 38 the valve openswide so that it offers no obstruction in the inlet passage.

The projection 40 extends a substantial distance into the interior ofthe bulb and, therefore, if a small amount of liquid should get into thebulb, it will not run into the valve and inlet orifice. The valve willthereby always remain dry and operable and will not adhere to its seatto cause non-functioning thereof. As stated hereinbefore, the extendedprojection 40 also spaces the valve 42 sufliciently inwardly and forms aprotection therefor so that when the bulb is compressed the valve willnot be distorted in any way. Further, the mass of rubber in projection40 is sufiiciently long and thick to render it relatively rigid incomparison with the flexibility of the thin walls of the bulb so thatthe valve seat is not distorted to cause leakage when the bulb issqueezed.

In the method of forming the present bulb, the two parts 30 and 31 aremolded separately as described. Upon removal from the mold the part 31is turned inside out and a cut 46 is made by a knife K, Figure 5,between the projection 40 and the extension step 42 to form the valve,using end surface 45 as a guide for the knife.

This cut is made in continuation of the plane of the end wall 45 of theprojection 40 and, after intersecting hole 38, extends substantiallythrough the extension 42 so that said extension readily bends relativeto the projection. The uncut portion forms a hinge 43 for the valve. Themethod described produces a valve which conforms exactly to its seat sothat a tight seal is provided between said valve and its seat whenpressure exists within the bulb. Even though great care is not taken inmaking the cut 46, the mating surfaces will, nevertheless, matchperfectly. It is found that the irregular serrations formed by the knifestrokes, which are greatly exaggerated in Figure 7, form a better airseal than two smooth, flat surfaces which have not been cut apart.

After the cut has been made the part 31 is turned right side out and theedges of the bulbs are then vulcanized together to form an integralstructure wherein the valve flap is integral with the bulb.

In some cases the knife marks may form relatively large ridges andvalleys and in other cases they may be almost microscopic in size, butthe size of the irregularities is not important as long as no materialis removed in the cutting operation. The nature of the irregularitiesdepends upon the condition of the knife blade and the technique of theoperator. The cut may be made in one stroke or several.

When the bulb is squeezed, the air pressure therewithin presses the flapagainst its seat in a perfect fit which cannot be obtained in any otherknown way. The fit of the flap against its seat is found to beabsolutely air tight, an achievement heretofore never attained in a dryflap valve which will provide an unobstructed air passage when openwide. The relative rigidity of the boss 40 and its considerable lengthinwardly of the bulb effectively isolates the seat from strains in thematerial when the bulb is squeezed whereby the most extreme deflectionof the bulb wall is not transmitted in any degree to the seat to producedistortion which would cause leakage. Metallic valve units haveheretofore been employed for this purpose which are subject to thedisadvantages hereinabove pointed out.

Figure 8 shows a modified form of bulb 10 having a thickened inlet endportion 50 with an outward projection or boss 51 and an inwardprojection 52. The boss 51 is provided with an inlet orifice or passage53 extending through a chamber 54 containing filter material 55. In thisembodiment, the inward projection is of less length than in the Figure 1embodiment, but, similar to that embodiment the inlet orifice extendsfrom the outer end of the member 51 inwardly and terminates short of theinner surface. A flap valve 56 is formed by making a cut 57 in the innerboss 52 in the manner described in connection with Figure 6, the cut forthe embodiment of Figure 8 being substantially coplanar with the innersurface of the bulb, the bulb being turned inside out and its innersurface utilized as a guide for the knife. The cut extends substantiallythrough the boss 52 but stops short sufliciently to provide a hinge 57for the valve 56, this cut intersecting the passage 53 whereupon theflow of air through said orifice is controlled by the valve. The methodof forming the bulb half shown in Figure 8 is the same as that describedabove, and this half is vulcanized to a half identical to the part 30 inFigure 2.

In the present invention there is thus provided an improved method forforming air bulbs, including the step of turning a bulb half inside outand cutting a valve flap from an integral part of the bulb so that theperfectly matching cut surfaces seat against each other when the valveis closed. It may be mentioned. in this connection that after thecutting operation the valve flap tends to spring closed and does nothang open, as shown in Figure 7 for convenience of illustration.

In this method of making the bulbs, the valve comprises an integral partthereof and is formed along with the manufacture of the bulbs, obviatingthe necessity for providing separate valve parts and making joints whichare subject to leakage. In addition to the facility and economy inmanufacturing, the bulbs of the present invention are eflicient inoperation. This efliciency results from the quick and wide open valvecharacteristics and the absence of a valve in the outlet passagewaywhere it would be particularly subject to sticking. The projection 40,while being formed of the same rubber material as the rest of the bulb,is sufficiently thick to be substantially non-distortable whereupon itwill always provide a true seating surface for the valve regardless ofthe manner in which the bulb is squeezed. The thickened projection 40,in addition to providing a good seat for the valve, also protects thevalve from interference by the walls of the bulb. The valve itself issufficiently thin to be readily responsive to pressure differentialsbetween the inside and outside of the bulb and to permit air to rush inquickly through the whole cross-sectional area of inlet orifice 38 andprevent objectionable backflow of air or fluid into the bulb. The pipefriction of the combined length of the stem of the bulb andcommunicating tubes and the orifice friction of the nozzles of theatomizer or nebulizer have a higher impedance to air flow than theorifice friction of inlet 38 to substantially prevent the backfiowmentioned without the use of check valves in the stem.

The present valve construction is also employed to advantage in othertypes of compressible chamber air pumps and in other organizationsrequiring valves. It is especially well suited for small hand pumps usedfor pumping air into inflatable devices.

Having now described my invention and in what manner the same may beused, what I claim as new and desire to protect by Letters Patent is:

1. A compressible molded rubber air bulb having a rounded shape andadapted, after being squeezed and released, to return to said roundedshape by the resilience of the rubber to produce suction, said bulbhaving inlet and outlet end portions vulcanized together, said inlet endportion having an inwardly extending boss molded integrally therewith,said boss being provided with a passageway opening through the outerwall of said bulb and extending inwardly to a point short of the innerend of said boss, the inner end of said boss being cut transverselysubstantially therethrough but leaving an uncut portion to provide anintegral flap valve at the inner end of said passage, said uncut portionof said flap valve forming a hinge for said valve, said boss having atransverse thickness sufiicient to cause it to be substantially rigidunder squeezing pressure applied to the bulb and said valve beingsufficiently thin to be flexible for opening and closing against saidboss, the movable edges of said valve being spaced from the sides ofsaid boss and guarded thereby from the sides of the bulb when the bulbis squeezed, said boss projecting into the interior of the bulb asufficient distance to space said valve from the end of the bulb, andsaid outlet portion having an air outlet passage therein.

2. A compressible molded rubber air bulb for a single valve atomizer andthe like having a rounded shape and adapted, after being squeezed andreleased, to return to said rounded shape by the resilience of therubber to produce suction, said bulb having inlet and outlet endportions vulcanized together, said inlet end portion having an inwardlyextending b'oss molded integrally therewith, said boss being providedwith a passageway opening through the outer wall of said bulb andextending inwardly to a point short of the inner end of said boss, theinner end of said boss being cut transversely substantially therethroughbut leaving an uncut portion to provide an integral flap valve at theinner end of said passage, said uncut portion of the boss forming ahinge for said valve, said boss having a transverse thickness suficientto cause it to be substantially rigid under squeezing pressure appliedto the bulb and said valve being sufiiciently thin to be flexible foropening and closing against said boss, the movable edges of said valvebeing spaced from the sides of said boss and guarded thereby from thesides of the bulb when the bulb is squeezed, said boss projecting intothe interior of the bulb a suificient distance .to space said valve fromthe end of the bulb, said outlet end portion of the bulb including anelongated tube molded integrally therewith, and having an unobstructedair discharge passage therethrough.

References Cited in the file of this patent UNITED STATES PATENTS138,416 Lockwood Apr. 29, 1873 204,469 Weed June 4, 1878 249,557Truesdell Nov. 15, 1881 451,179 Ware Apr. 28, 1891 834,185 Cambell Oct.23, 1906 1,315,955 Gill Sept. 16, 1919 1,576,128 Ballard Mar. 8, 19262,213,522 Holmboe et a1 Sept. 3, 1940 2,362,215 Morreale Nov. 7, 1944FOREIGN PATENTS 87,109 Switzerland Nov. 1, 1920

